Refrigeration apparatus



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Nov. 3, 1964 R. r. DOUGLAS REFRIGERATION APPARATUS Original Filed June 2, 1958 United States Patent O REFRGERATON APPARATUS Richard T. Douglas, Hilliard, Ohio, assigner to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Continuation of application Ser. No. 739,316, lune 2, 1958. This application Dec. 27, 1961, Ser. No. 163,384

Claims. (Cl. 23h- 2.32)

This application is a continuation of my copending` application Serial No. 739,316 tiled lune 2, 195 8, now abrandoned and assigned to the assignee of this continuing application.

This invention relates to motor-compressors for refrigerators and more particularly to means for reducing noise in motor-compressors that are hermetically sealed in a shell containing .a body of lubricating oil.

In conventional motor-compressors of the type supportedon spring mounts within ya hermeticaly sealed shell and partially immersed in lubricating oil, sound Waves from the motor-compressor are transmitted through the oil to the shell Walls, thus causing objectional noises to emanate from theshell.

In -accordance with .the present invention the intensity of the objectional noises is greatly reduced in motor-com pressors of the type set forth by aerating the oil body with all or part of the suction gas that enters the shell. Since a body of liquid is many times more effective in transmitting `sound Waves than =a body of gas, aeration of the oil body with suction gas results in a mixture of oil and gas bubbles that is a relatively poor sound conductor, thus affording a substantial noise reduction. In addition, the oil muffles the hissing sound of thesuction gas issuing into the shell.

The Various objects, features, and advantages of the invention will Iappear more fully from the detailed description which follows, taken in connection with the accompanying drawings, forming a part of this application, in which: i' i FIG. l is .a vertical sectional side view of the shell of a motor-compressor unit, constructed and arranged according to the invention, and showing the parts disposed -interiorly thereof in elevation;

FIG. 2 is a vertical sectional end view of the apparatus of FIG. 1, taken along the line II--II of FIG. l; and

FIG. 3 is a fragmentary vertical sectional side View of the shell of a motor-compressor unit embodying the invention, but showing in elevation an alternate construction and arrangement of internal parts.

The motor-compressor 11 forms part of a conventional refrigeration circuit (illustrated diagrammatically in FIG. l) and is enclosed in a hermetically sealed vessel or shell 12 having a suction conduit 13 and a compressed gas conduit 14 which respectively provide an inlet for admitting expanded refrigerant gas to the shell and an outlet for compressed refrigerant gas. The motor-compressor 11 is of the horizontal taxis, reciprocating type, resiliently mounted on supporting brackets 18 by means of several helical compression springs 19 and partially immersed in a body 17 of lubricating oil. The motor-compressor 11 is supported in yspaced relation to the shell 12.

Lubrication of the motor-compressor 11 is accomplished by a well-known splash system comprising a kicker 21 which is secured Ato a piston rod 22 of the compressor and extends downwardly therefrom into the oil body 17. During operation of the motor-compressor 11, the kicker 21 reciprocates rapidly through the oil body 17, causing oil to splash on neighboring parts and lubricate them. Other lubricant conveyors, such as pumps, may also be employed with motor-compressor units of this type.

One of the disadvantages of lubricating systems in which 3,155,312 Patented Nov. 3, -1964 ICC Y a body of oil is maintained within the motor-compressor shell is that the oil body 17 provides a fairly effective medium for transmitting sound Waves from the motorcompressor 11 to the shell 12, thus causing objectional noises to emanate from the shell. It is well known that the intensity of sound emanating from a structure to which kinetic energy has been transferred through a connecting medium is directly proportional to the velocity with which the transmitting medium can transmit wave energy. For example, metal is an excellent transmitting medium for sound waves, `and a gas, such as gaseous refrigerant, is a poor medium. Similarly, a body of oil or liquid is capable of transmitting Wave energy at many times the velocity of refrigerant gas and, for this reason, hermetically seal-ed, spring-supported motor-compressor units which are partially immersed in a body of lubricating oil are usually noisier than resiliently supported motor-compressors that are not immersed in oil.

In order to render the oil body 17 a less effective sound transmitting medium, provision is made to utilize refrig erant gas for aerating the oil body, thus employing hundreds of gaseous bubbles as dynamic sound insulators. Suction gas is delivered to the interior of the yshell 12 by the suction conduit 13, and at least a portion thereof is further conducted well beneath the surface of the oil body 17 by means of an extension tube 25. The tube 25 has Vaterminal portion extending beneaththat portion of the motor-compressor 11 which is immersed in the oil body, and this portion of the tube is perforated along its length lto provide outlet openings. One embodiment of the invention as thus far described is illustrated in FIG. 3, wherein all ofthe suction gas passing through the extension tube 25 is bubbled through the body of oil to the surface thereof, from whence it is drawn into the compressor inlet 26, compressed, and discharged through the compressed gas conduit 14. The embodiment of FIG. 3, in bubbling all of the incoming suction gas through the lubricating oil, may cause a violent bubbling action which, by itself, can be a source of suiiicient objectional noiseto partially Aoffset the advantages gained.

The preferred embodiment of this invention, illustrated Y in FIGS. l and 2p, incorporates an outlet opening 27 in of oil and the remaining portion thereof aerates the oil by bubbling therethrough, mildly and quietly. It has been determined that, for fractional horsepower motor-compressors such as are employed in domestic refrigerators, directing approximately 20 percent of the suction gas through the body of oil and permitting the remaining gas to discharge directly into the shell results in maximum noise reduction. As can be readily appreciated, of course, the division of gas flow is determined by the relative flow areas of, respectively, the outlet opening 27 and the perforations in the extension tube 25.

Additionally, hissing noises often accompanying the issuance of suction gas into the shell 12 are muffled by bubbling the gas through the oil body 17.

From the foregoing it will be apparent that the invention provides for reduction in the amount of noise transmitted from the motor-compressor unit to the shell within which it is sealed via the body of lubricant, such noise reduction being effected by aeration of the lubricant body to reduce its effectiveness as a sound-transmitting medium. Further, it will be apparent that, in accordance with this invention, satisfactory and inexpensive aeration of the lubricant for this purpose may be accomplished by bubbling all or a portion of the suction gas through the body of lubricant.

While the invention has been shown in several forms, it will be obvious to those skilled in the art that it is not 3,1 5,31 2 3 d so limited, but is susceptible of various other changes an outlet conduit for discharge of refrigerant gas thereand modifications without departing from the spirit therefrom;

What is claimed is:

of. .t of means for reducing the transmission of noise from lsaid unit to said shell via said body of lubricant,

l. Refrigeration apparatus comprising 5 said last-mentioned means comprising a motor-compressor unit, an extension tube connected to said inlet conduit and a sealed shell housing lsaid unit, having at least abody of liquid lubricant in said shell, a portion thereof extending into said body of lubricant means resiliently mounting said unit in said shell in beneath the portion of said unit contacted by said spaced relation to the latter with a portion of the lubricant, said `portion of said extension tube havunit submerged in said body of lubricant, and ing Y means for aerating said body of lubricant to reduce a plurality of perforations therein through which gas the ability of the latter to transmit noise from the is discharged into said body of lubricant. unit to the shell. 5. The combination with;

V2. Refrigeration apparatus comprising a motor-compressor unit,

a motor-compressor unit, a sealed shell housing said unit,

a Sealed Shell llOUSiDg Said unit, means resiliently mounting said unit in spaced relation a body of liquid lubricant in said shell, to said shell,

means resiliently mounting said unit in said shell in a body of lubricmt Within said Shen and contacting a spaced relation to the latter with a portion of the Portion of Sal-d unit and a portion of Said Shen umt SubmPrgef m Said body .of lubncam an inlet conduit for admitting refrigerant gas to the means for directing gaseou-s refrigerant to the interior Shen and of the shell, and dt d .tf d. h f f th means for mixing at least a portion of said gaseous rean ou con u1 or Isc arge o Ie ngerant gas ere', frigerant with said body of lubricant to reduce the from v ability of the latter to transmit noise from the unit to of leans for redllclrlg the transmission of noise -from the Shell` said unit to said shell Via said body of lubricant,

3. Refrigeration apparatus comprising Said last-mentioned means comprising a motel-.compressor unit, an extension tube connected to said inlet conduit, said a sealed shell hou-sing said unit, extension tube having a body of liquid lubricant in said shell, one portion thereof above the ysurface of said body of means resiliently mounting said unit in said shell in lubricant and SPlCed relation t0 the latter With a POrOrl Of ille another portion thereof below said surface beneath Urllt submerged irl Said body 0f lubricant and the portion of said unit contacted -by said lubricant,

meansfor aerating Said body O f lubricant with gaseous each of said extension tube portions having at least refngerant to pmquce a mxture of lubricant and one perforation therein for discharge of refrigerant gas bubbles that is a relatively poor sound coiigas therefrom ductor, thereby effecting a substantial noise reduc- 4. @gli Combination with; 40 References Cited in the le of this patent a se e s e ousing sai unit,

means resiliently mounting said unit in spaced relation 1348828 Fssenden Aug' 3 1920 tosaid Shen, 1,845,551 MIZI Feb. 16, 1932 ansltanduit for admitting refrigerant gas to the 2,767,903 Warner Oct. 23, 1956 

1. REFRIGERATION APPARATUS COMPRISING A MOTOR-COMPRESSOR UNIT, A SEALED SHELL HOUSING SAID UNIT, A BODY OF LIQUID LUBRICANT IN SAID SHELL, MEANS RESILIENTLY MOUNTING SAID UNIT IN SAID SHELL IN SPACED RELATION TO THE LATTER WITH A PORTION OF THE UNIT SUBMERGED IN SAID BODY OF LUBRICANT, AND MEANS FOR AERATING SAID BODY OF LUBRICANT TO REDUCE THE ABILITY OF THE LATTER TO TRANSMIT NOISE FROM THE UNIT TO THE SHELL. 